The invention is directed to a composition and the method of its preparation for use in temporarily masking surfaces where protection is desired a) from marring during later steps of manufacture (b) for chemically selectively etching portion(s) of a surface while shielding the balance and (c) for selectively exposing portion(s) of a surface to spray painting or the like while keeping other areas from being painted. Specifically, it provides a strippable coating which becomes tack free at about 150.degree. F. in about 10 minutes and is fully strippable after about 20 minutes at about 350 .degree. F.
The composition and its use provides: masking that does not involve noxious solvents either in application or removal, masking that is simply curable by heating in one or two steps and masking that is capable of a high degree of definition for precision work.
Many techniques and compositions have been developed in the past for selectively masking a work surface for defining areas to be chemically etched, painted or otherwise treated. Masking tape is well known for this purpose as is solvent borne rubber. Most of the prior techniques and compositions utilize solvents to carry the masking material prior to coating the work surface and subsequently require solvents to remove the masking layer from the work surface after the use of the masking has been accomplished. Another common masking procedure involves radiation curable coatings that can be selectively cured using photographic procedures. One such procedure that produces a coating that can be mechanically stripped is described in U.S. Pat. No. 4,826,705 to Drain et al. While such prior techniques are usable they have disadvantages such as the recurring use of large amounts of solvents, both to apply and to remove the coating and complex curing procedures such as that of Drain et al.